Clinical Presentation

Acute overdosage with oxymorphone is manifested by respiratory depression, somnolence progressing to stupor or coma, skeletal muscle flaccidity, cold and clammy skin, constricted pupils, and, sometimes, pulmonary edema, bradycardia, hypotension, and death. Marked mydriasis rather than miosis may be seen due to severe hypoxia in overdose situations.

Treatment of Overdose

In case of overdose, priorities are the re-establishment of a patent and protected airway and institution of assisted or controlled ventilation if needed. Employ other supportive measures (including oxygen, vasopressors) in the management of circulatory shock and pulmonary edema as indicated. Cardiac arrest or arrhythmias will require advanced life support techniques.

The opioid antagonists, naloxone or nalmefene, are specific antidotes to respiratory depression resulting from opioid overdose. Opioid antagonists should not be administered in the absence of clinically significant respiratory or circulatory depression secondary to oxymorphone overdose. Such agents should be administered cautiously to patients who are known, or suspected to be, physically dependent on OPANA ER. In such cases, an abrupt or complete reversal of opioid effects may precipitate an acute withdrawal syndrome.

Because the duration of reversal would be expected to be less than the duration of action of oxymorphone in OPANA ER, carefully monitor the patient until spontaneous respiration is reliably reestablished. OPANA ER will continue to release oxymorphone adding to the oxymorphone load for up to 24 hours after administration, necessitating prolonged monitoring. If the response to opioid antagonists is suboptimal or not sustained, additional antagonist should be given as directed in the product's prescribing information.

In an individual physically dependent on opioids, administration of an opioid receptor antagonist may precipitate an acute withdrawal. The severity of the withdrawal produced will depend on the degree of physical dependence and the dose of the antagonist administered. If a decision is made to treat serious respiratory depression in the physically dependent patient, administration of the antagonist should be begun with care and by titration with smaller than usual doses of the antagonist.

OPANA ER is contraindicated in patients with:

• Significant respiratory depression
• Acute or severe bronchial asthma or hypercarbia
• Known or suspected paralytic ileus
• Moderate and severe hepatic impairment [see CLINICAL PHARMACOLOGY, WARNINGS AND PRECAUTIONS].
• Hypersensitivity (e.g. anaphylaxis) to oxymorphone, any other ingredients in OPANA ER, or to morphine analogs such as codeine [see ADVERSE REACTIONS].

Last reviewed on RxList: 7/27/2012
This monograph has been modified to include the generic and brand name in many instances.